Additionally, people may have been exposed at the Joondalup Health Campus emergency department from 8.15pm on Tuesday, October 23 to 6.30am on Wednesday, October 24.

Director of Communicable Diseases Dr Paul Armstrong said public health staff had provided information to people who were potentially exposed to the most recent case where they were known, but it was not possible to identify and specifically warn people who were in public places.

“Unfortunately, it was not unusual for Australians, especially young adults, to be infected with measles overseas,” he said.

“Every imported measles case is treated as a public health emergency because of the risk of local spread – including to those most vulnerable to infection, such as infants too young to be vaccinated, pregnant women and those with compromised immune systems.

“With high vaccination coverage, naturally occurring measles has been eliminated from WA for around 20 years, but occasional cases and small outbreaks still occur – associated with tourists or WA residents who are infected overseas.

“People planning to travel overseas should make sure they have been appropriately vaccinated against measles and other vaccine-preventable diseases.”

Anyone who has had a potential exposure to measles, and who develops a fever with other symptoms – including cough, runny nose, sore red eyes and a rash – should consult their doctor.

Dr Armstrong said anyone who thought they might have measles should call ahead so that they can be isolated when arriving at the doctor’s surgery or hospital.

This helps prevent infecting other patients and staff.

“Measles is contagious for about four days before and after the development of the rash. Children and adults who have been unwittingly exposed are at risk of developing measles if they are not immune,” he said.